1. Field of the invention
The present invention relates to a display system, especially that for a camera system.
2. Prior art
Film speed is one of parameters that is necessary to determine an exposure condition of a photographing. An automatic film speed reading mechanism is already known where the film speed of a film is printed on the film cartridge (DX code) and an array of electric contact points provided in a camera body detects the film speed. For skillful photographers, a manual film-speed setting switch (or dial) is provided on some types of camera to override the automatically read film speed value.
Besides film speed, there are many parameters that affect an exposure condition, e.g., aperture value, shutter speed, exposure override setting, etc. These parameters should be displayed on the camera body (or on an attachment of the camera such as a special back cover of the camera body) so that the photographer could expect the exposure condition of the picture. There are two types of displays: one is a dot matrix display and the other is a segment display. The dot matrix display is composed of a two-dimensional array of a large number of small dots (pixels), and the segment display is composed of a comparatively small number of segments which have normally certain predetermined shapes. The dot matrix display is versatile (i.e., gives a large freedom of presentation) but consumes more energy. The segment display is not so versatile in presentation but consumes less energy. Some cameras use both display systems (dot matrix and segment displays) in one body.